1. Field of the Invention
The present invention relates to an idle control system for a fuel cell vehicle, and in particular relates to an idle control system for a fuel cell vehicle, which is installed in a hybrid-type power supply provided with a fuel cell and a power storage device which is recharged by generated current from the fuel cell.
2. Description of the Related Art
Heretofore there is known a fuel cell vehicle provided with a solid polymer membrane-type fuel cell, in which the responsiveness of the output supply to each part of the vehicle is increased by providing a power storage device comprising for example a battery or a capacitor and the like, in order to supplement the output responsiveness of the fuel cell accompanying the gas supply of hydrogen gas as a fuel and air as an oxidizing gas.
As such a fuel cell vehicle there is for example one disclosed in Japanese Unexamined Patent Application, First Publication No. 2001-359204, which is provided with an idle control system which detects an idle state where it is possible to stop power generation of the fuel cell, and stops power generation of the fuel cell, and resumes power generation of the fuel cell when the state of charge of the power storage device is less than a predetermined state of charge.
However, in the conventional technology, the target amount of power generated in the case of resuming power generation of the fuel cell is set depending on the state of charge of the power storage device and the expected power consumption of the electrical load of the vehicle. Therefore, the amount of power generated by the fuel cell fluctuates depending on the state of the electrical load, and hence there is no appreciable increase in the efficiency of power generation by the fuel cell. Also, there is concern that the amount of noise generated by the air supply compressor which supplies the reaction gas air to the fuel cell, fluctuates depending on the target amount of power generated by the fuel cell.
In particular, in cases where the state of charge of the power storage device is low, and where the expected power consumption of the electrical load of the vehicle is high, the target amount of power generated by the fuel cell is increased. However, a supply of reaction gas to match to the increase of the amount of power generated by the fuel cell is necessary, and hence the power required by the air supply compressor also increases. Therefore, as the amount of power generated by the fuel cell becomes greater, the power consumed in order to drive the compressor is increased, and there have been problems with a reduction in the overall efficiency of power generation.